Yazio vs Lifesum vs Simple vs Swoodie 2026: Best Apps for Intermittent Fasting & Wellness

Intermittent fasting has stopped being a fad and become a feature — and four apps keep showing up when people ask which one to use alongside the rest of their nutrition. Yazio, the calorie counter with the most polished IF tracker on the market. Lifesum, the Swedish wellness platform that wraps fasting inside a broader library of diet plans. Simple, which turned its fasting timer into a chat-based AI coach. And Swoodie, which added a fasting tracker, a fasting coach and partner-synced windows in v1.4 on top of a full recipe and meal-planning app.

They all time your eating window. That is roughly where the similarity ends. This is the honest four-way — what each app is genuinely good at, and which one fits the way you actually want to fast.

The 60-second verdict

• Pick Yazio if you want the most mature, polished intermittent-fasting tracker on the market, with calorie counting in the same app.
• Pick Lifesum if you want fasting embedded in a broader wellness platform with diet-plan variety (keto, Mediterranean, high-protein, and so on).
• Pick Simple if you want fasting framed as a conversation with an AI coach (“Avo”) rather than a screen of numbers.
• Pick Swoodie if you want fasting plus a full recipe and meal-planning app — and the option to sync your fasting window with a partner.

How we compared them

Pricing and feature figures below come from each app’s own listing, checked in 2026. We focused on the question screenshots tend to skip: how usable each free tier really is, what the app gives you outside the fasting window, and what happens when you want to fast with someone else.

Free tier: the real differentiator

A fasting timer is a simple thing. What matters is what each app puts behind a paywall around it.

• Yazio: a free tier with basic calorie logging, a barcode scanner and the IF timer itself, supported by ads. The mature recipe library, AI photo recognition (added in 2026) and the advanced fasting features sit behind Yazio Pro.
• Lifesum: a free tier with calorie logging and a small slice of the platform. The fasting timer integrated with Lifesum’s diet plans, the broader recipe and plan library, and the personalized programs are Premium.
• Simple: a free tier exists for basic fasting tracking, but the product is really the conversation with Avo, the AI coach — and that sits on the paid subscription.
• Swoodie: the fasting tracker itself is free, with all six protocols (12:12, 14:10, 16:8, 18:6, OMAD, custom), a live timer and history. The full 8,000+ recipe library and basic meal tracking are also free with no account. Fasting Coach nudges and Fast Together (partner sync) are Premium; AI features come as a 5-use free trial, then Premium.

For pure fasting, three of the four (Yazio, Simple, Swoodie) give you a usable free timer. Swoodie stretches the free tier the furthest into the rest of the kitchen — full recipe library and basic tracking, no account required.

Protocols and the timer experience

Yazio has had years to polish its IF screen and it shows. The protocol picker is quick, the daily and weekly view is calm, and the long-term history is one of the better ones in the category — genuinely the most mature IF UI of the four. If polish is the criterion, Yazio wins this section honestly.

Lifesum integrates fasting into its diet-plan framework rather than treating it as a standalone product — the timer lives next to your daily plan, your macros and your selected diet (keto, Mediterranean, high-protein, and others). For people who want fasting as one ingredient inside a broader plan, that integration is the appeal.

Simple treats fasting less as a timer and more as a coaching conversation. Avo nudges, summarizes and answers questions in chat; the timer is there, but the experience is the dialogue around it. Whether that is brilliant or noisy depends on how much you want a chatbot in your fasting.

Swoodie ships six protocols (12:12, 14:10, 16:8, 18:6, OMAD, custom) with a live timer and history, and adds Ollie’s Fasting Coach on Premium — small nudges, milestone notes and the occasional well-timed quip inside the window. The timer itself is deliberately simple; the personality is the optional upgrade.

Beyond the timer: what else each app does

This is the second-app question. A fasting timer counts down hours. It doesn’t help you decide what to eat when the window opens, or what to cook tomorrow.

• Yazio: calorie tracking plus a recipe library behind Pro. One app for fasting and counting; lighter on planning and cooking inspiration.
• Lifesum: calorie tracking plus diet plans (keto, Mediterranean, high-protein and so on), recipes built into the plans, and fasting layered on top. The broadest wellness positioning of the four.
• Simple: mostly the coaching conversation. Avo can answer questions about what to eat or how to break a fast, but the app is the chat rather than a recipe browser or planner.
• Swoodie: fasting plus the full kitchen — 8,000+ recipes, AI recipe generation (Chef AI), an AI meal planner, an auto shopping list, calorie and macro tracking, photo and barcode logging, Swipe Together for couples and Nest for households up to six.

If you only need fasting and basic counting, Yazio is enough. If you want diet-plan structure around it, Lifesum is the most natural fit. If you want a coach to talk to, Simple is its own category. If you want one app that handles fasting and what you actually cook, Swoodie is the broadest of the four.

Fasting with a partner

This is the section where the four apps diverge most sharply.

• Yazio: no synced partner fasting. Your timer is yours.
• Lifesum: no synced partner fasting either — plans are personal.
• Simple: the conversation with Avo is a one-on-one with the AI, not with another human on the same clock.
• Swoodie: Fast Together — a real synced window. Host an invite (Premium) and your partner joins for free; both timers show the same start, the same end, the same milestones, and you can send a clap when the window closes.

The difference is small in theory and large in practice. A shared chat or community keeps you generally motivated; a synced window means you and one specific person break the fast at the same minute. For couples and accountability pairs, that is a different kind of habit.

Pricing: and the two-year picture

• Yazio Pro: around $47.90/year.
• Lifesum Premium: around $44.99/year.
• Simple: $14.99/month or around $59.99/year — the most expensive of the four.
• Swoodie Premium: $9.99/month or $39.99/year, with a 3-day trial on the annual plan and a $3.99 weekly option — the cheapest annually of the four.

Over two years Swoodie Premium runs about $80, against roughly $90 for Lifesum, $96 for Yazio and $120 for Simple — and Swoodie is the broadest of the four, with the full recipe and planning stack on top of fasting. The question isn’t whether to pay; it is which annual price you pay for which surface area.

Where Swoodie falls short

In fairness: Yazio’s intermittent-fasting UI is more mature — years of polish on a single screen that a v1.4 tracker simply cannot claim. If “most polished IF screen in the App Store” is your one criterion, that is Yazio. Lifesum’s diet-plan library has depth a single-app meal planner does not match if your structure comes from following a specific protocol week by week. And Simple’s Avo coaching is its own thing — a conversational interface that, if it works for you, has no real analog in the other three apps. Swoodie’s argument is breadth and integration — fasting inside a full kitchen, with a synced window for the one person you actually fast with, at the lowest annual price of the four — not being the most established IF-only brand or the most polished chat coach.

Which one for your goal?

• Most polished IF tracker, fasting + calorie counting: Yazio.
• Fasting inside a broader diet-plan platform: Lifesum.
• Fasting as a coaching conversation: Simple.
• Fasting plus a full recipe and meal-planning app in one place: Swoodie.
• Fasting with a partner on a synced clock: Swoodie — Fast Together is unique here.
• Lowest annual cost for the broadest feature set: Swoodie — $39.99/year.

A quick scenario

The couple starting 16:8 together. You both want to try intermittent fasting, but the moment one of you eats at 11 and the other at noon, the “we’re doing this together” story falls apart. Yazio will time each of you separately on a beautiful screen. Lifesum will fold fasting into each of your personal plans. Simple will give each of you a coaching chat. Swoodie’s Fast Together gives you both the same window on the same clock, with the same recipes ready when it opens: which is what “together” was supposed to mean.

Deeper one-on-one breakdowns

Swoodie vs Yazio · Swoodie vs Lifesum · Swoodie vs Simple · All alternatives

Related: Zero vs Fastic vs Swoodie · MyFitnessPal vs Yazio vs Swoodie · Intermittent fasting with Swoodie

Try Swoodie free on iOS or Google Play — no account needed; fasting tracker is free, AI features have a 5-use free trial, no card.